Today marks the start of the new financial year, when a series of measures announced by the chancellor in the budget take effect. This makes it a good time to review your retirement planning, savings and investments with a host of new allowances on offer. "It makes sense to decide how you might use these early in the year rather than leaving it to the last minute, and potentially being rushed into making mistakes," says Patrick Connolly, from independent financial adviser Chase de Vere. "This way, you also give your money more time to grow." Here we offer guidance on how to make the most of the new rules:

What is the best option to save for retirement?

The dramatic changes to Isas and pensions announced over recent weeks has reignited the debate about which is a better option for retirement planning. The flexibility of tax-efficient Isas appeals to many people, enabling you to withdraw money when you like and use it as you wish. However, budget reforms give you freedom to spend your pension pot as you wish from April next year. Previously, the majority had used their pension fund to buy an annuity, a financial product that pays an income for life that is considered to offer poor returns.

Most experts say that for people who can afford it, a combination of saving into both Isas and pensions is the best strategy. Higher-rate and additional-rate taxpayers continue to benefit most from pensions because of the immediate tax relief. For every £1,000 you save, the government adds £250, while higher-rate taxpayers can reclaim up to a further £250 in tax relief through their tax return.

"Contributing to a pension gets you income tax relief on the way in, tax-efficient investments within the pension fund itself, and a 25% tax-free lump sum on retirement," says Martin Bamford from independent financial adviser Informed Choice.

Pensions also offer a disciplined way of saving, with no access to the fund until age 55 which prevents spending it too early. And if your employer offers a contribution to your pension in a workplace scheme it is a clear advantage.

In contrast, Isa accounts miss out on the upfront relief, but allow savings to grow tax free, and the whole pot can be taken completely tax free whenever you want. "For many, Isas are preferable when they are younger, when they are earning less and might need to access their money. However, pensions come to the fore as people age, earnings increase and they become more focused on retirement," says Connolly.

I want to pay less tax. How can I do this?

Putting any spare cash in an Isa is the simplest way following a radical overhaul in the budget. From today, the sum you can save rises from £11,520 to £11,880. At present, only half of this can be held in a cash Isa, while the full allowance can be put in a stocks and shares Isa. However, 1 July heralds the birth of the "new Isa", or Nisa, enabling savers to stash £15,000 away to earn tax-free interest. Even better, you can invest as much as you want of this in either cash or stocks and shares, and transfer freely between the two. For the first time you will also be able to transfer previous years' funds from stocks and shares Isas into cash Isas. Any Isas you open before 1 July will automatically become Nisas. You will then be able to add further savings up to the new £15,000 limit.

Outside Isas, other tax-efficient wrappers include pensions, while venture capital trusts and enterprise investment schemes offer attractive tax breaks for those willing to take greater risks by investing in fledgling companies.

Another simple option for couples is to hold savings or investments in the name of the person in the lower tax bracket. Turning to capital gains tax, consider if you are likely to use the new £11,000 allowance, as this cannot be carried into the next tax year. A couple can make gains of up to £22,000 in the new tax year before they become liable to CGT, as each person is entitled to an allowance.

What about saving for my children?

You can take advantage of a tax- efficient Junior Isa, offering a wide range of investment options. The amount you can save has increased from £3,720 to £3,840, and will rise again to £4,000 from 1 July. "If you are paying into a Jisa, you might want to look at changing regular contribution amounts considering this increase," says Danny Cox from financial services provider Hargreaves Lansdown.

But there is one major caveat attached to Jisas, warns Connolly. "At age 18 the child can access the money and spend it however they want," he says. This risks money, put aside to pay for university fees or mortgage deposits, being squandered on foreign holidays and cars. To guard against this you could consider options such as using your Isa allowance to save for your child, trust arrangements; or holding funds in your child's name. "I'm in favour of parents using a designated savings or investment account," says Bamford. "This might be taxable, but it places control in the parent's hands."

How do I get the best from my pension at retirement?

As in previous years, you are able to take a quarter of your pension fund as a tax-free lump sum. You used to have six months to arrange what to do with the remainder. This typically meant deciding whether to buy an annuity or going into drawdown, leaving the fund invested and taking an income. The Treasury says it has extended the period to 18 months. However, Tom McPhail, pensions expert at Hargreaves Lansdown, suggests those approaching retirement should contact their scheme provider to confirm this. "Changes have happened so quickly and the rules aren't that clear cut."

If you opt for drawdown you can withdraw higher levels of income if you need them following changes last month. "This amounts to broadly one-and-a-half times what you might receive from an annuity," says Cox.

There are fresh options. From January 2015, pensioners will be able to put up to £10,000 a year in a new bond run by the government-backed National Savings & Investments. The chancellor promised that interest rates would be "market-leading", and could start at 2.8% on a one-year bond and 4% on a three-year account. Anyone aged 65 and over will be allowed to invest up to £10,000 in each product.